.wrapper {
  box-sizing: border-box;
  width: 100vw;
  height: 85vh;
  
}
.wrapper > div {
  box-sizing: border-box;
  padding: 10px;
  overflow: hidden;
  outline: 1px solid gray;
}

.header-wrapper {
  width: 100vw;
  height: 15vh;
  
  float: left;
}

.nav-wrapper {
  width: 20vw;
  height: 85vh;
  float: left;
}

.content-wrapper {
  box-sizing: border-box;
  width: 80vw;
  height: 85vh;
  float: left;
}

.copyright {
  position: fixed;
  bottom: 5vh;
  left: 40vw;
}